What's going on behind the scenes when Vodafone 4G goes live in each city? That's exactly what we've asekd Yago Tenorio - Vodafone UK's head of networks.

“As we speak, we are finalising the build of our London 4G network,” says Yago Tenorio, head of networks at Vodafone UK. It’s all go for him and his team right now, as we prepare for the launch of 4G on 29 August.

But when you’re adding 4G to the network, what’s actually going on behind the scenes? We’ve been quizzing Yago to find out.

A two-pronged attack

“The work at the core of the network is complete; now we’re focused on the local activity. On our existing sites we need to upgrade the antennas and the equipment,” Yago explains. “So, engineers have to go to the site and change the electronics. Depending on the site, that may be quite difficult, particularly in London.

“Antennas are the most difficult because they’re big and bulky, and sometimes require a crane. The radio equipment is generally easier, but even then you sometimes have to build new cabinets or find unique solutions to problems.

“That’s the key to 4G – putting in the electronics and the antennas that can deliver our 4G service. At the same time, we’ve been working on bringing fibre optic cables to our sites, so that they have very high-speed connections.”

Yago tells us that there are hundreds of sites in London alone, and while it’s been a huge job to fit all the nuts and bolts needed for 4G, that’s only half of the story.

“We have one team finishing the rollout by installing the last bits of kit on our mast sites, and we have another team working to get it live. There’s a two stage approach for testing. We have crews of people on foot and in vehicles, patrolling London constantly, and testing each site as it goes live. They carry specially designed handsets with network tracing capabilities which we use to test data connections and speeds.

“There’s another process we use to monitor how the network is behaving in London as a whole and we use this as part of our quality assurance work. It’s similar to the kind of thing you’d see in a manufacturing plant – every ‘unit’ leaving the factory goes through stringent quality controls.

“We have our entire team on the ground, going from site to site to make sure that everything is ready.”

The big day

Those two strands of Yago’s team are working in harmony to get everything ready for the initial rollout in London, but we wanted to know more about the big day itself. What will actually happen to allow us to access 4G on 29 August?

“Most of the sites themselves are prepared already and the coverage in London is almost complete. But no one can experience it yet – it’s there, but it can’t be used yet.” And why’s that? “Because even if you have a 4G device, we have controls in place so that you can’t access it until we’re absolutely ready.

“You can currently only access it if you have a special SIM like our network testing team and engineers do,” Yago says. “Our 4G network is there ready, but your phone won’t see it yet.”

That’s until the big day itself…

“Late on 28 August or very early on 29 August, we’ll have people out in the field, and when London’s (mostly) sleeping we’ll open up our 4G network. That means that our customers in 4G areas, with 4G-ready phones and on a 4G price plans will be able to reset their devices in the morning and connect to the new service.”

The right approach to 4G

Vodafone’s 4G network is launching in London first, before moving onto a slew of other cities by the end of the year. Beyond that, we’re looking to provide coverage using 2G, 3G or 4G services to 98% of the UK population. But why the staggered approach?

“How you roll out a network depends on what your aim is,” Yago says. “If you want to claim that you’ve launched in many, many cities you just put a few sites in the centre and say ‘I’m here’, even if your coverage isn’t that good. That’s just a game of claiming.

“Our aim is to give our customers the best experience. So we’re only going to launch the service in each city once we’ve made sure the service is worth having. We’re launching first in London where we’ll make sure our 4G coverage is fantastic. Then we’ll carry on with the rest of the cities and beyond.”

“This is not the end of anything; it’s just the start.”

But that doesn’t mean that we’re only working on one place at a time. Far from it: “We’re already working across multiple cities at the same time,” Yago adds. “But we’ll only launch once we know our customers are going to feel the difference, and that they’re going to be satisfied.

“This is not the end of anything; it’s just the start. The network will always evolve, but we want the start to be really good. That’s why we’re holding on until we know that the experience is right.”

But what does a good experience look like? As you can imagine, if we want everyone on Vodafone’s 4G network to feel the benefit, we’ve got to have our standards set pretty high:

“We’re aiming to cover a very high percentage of London with what we call ‘indoor 4G’. We can do that because we’re using a signal frequency that’s best placed to give our customers a similar indoor network experience to their outdoor connection. That’s using the 800Mhz spectrum that we bought through Ofcom’s auction earlier this year. We worked hard to get this spectrum because we know how important getting service indoors is to our customers, both at home and in the office.

“But this is just the beginning,” he says in closing. “We’ll keep working to improve our network and our customers’ experience.